How long and how strong must a climatic anomaly be in order to evoke a social transformation? Historical and contemporaneous case studies

In recent years, scholarly interest in the nexus between climate change and human societies has risen dramatically. This article asks: what type of climatic anomalies can undermine social stability, and what duration and intensity are necessary to instigate structural change? Contrary to a focus on short, dramatic events (storms, mudslides), the authors argue that gradual and more "usual" anomalies—prolonged droughts, cold spells, or untimely rains—have deeper, long-term impacts by reducing food availability. Based on qualitative examinations of collapse periods in western Asia and northern China (11th–early 12th centuries) and a high-resolution re-examination of Mali’s 2010s crisis, they contend that extended anomalies affecting food supply accelerate decisive processes, spur migration, increase violence and religious extremism, and lead to structural societal changes.